150 
NATURE 
[APRIL II, 1912 
forty-two cones, the sixth of twenty-eight high cones, | 
while the seventh group had disappeared, probably 
beneath the lava-streams. The Circumetnean railway 
was occupied by the lava-streams for a length of 
800 metres, the lava being piled up over it to a 
height of 30 metres. The front of the lava reached 
the Vallone Crasso, about 2 km. beyond the railway. 
Great quantities of sand and ashes were erupted 
continuously from the central crater, especially be- 
tween September 11 and 16. On the days on which 
the dust fell over Catania, the air was thick, the sun 
and moon near the horizon were redder than usual; 
sometimes also the sun, when high up, was reddish 
and surrounded by a reddish-yellow aureole; but there 
was no sign whatever of a Bishop’s-ring. 
D 
WATER RESOURCES OF THE UNITED 
STATES.* 
(GC SESONEED with eight water supply papers, 
varying in size from 78 to 370 pp., embracing 
an area of country which is half the United States, 
and exhibiting a comprehensiveness of treatment 
which covers river-gauging, well-sinking, water 
analysis, irrigation, topography, physiography, 
geology, and meteorology, one is constrained to admit 
that any attempt to do justice to such a mass of 
material within the brief compass of a short notice 
is an impracticable proceeding, foredoomed to failure. 
It will only be possible, in fact, to turn over the 
numerous pages of carefully recorded data and valu- 
able information, and pick therefrom, almost at 
random, one or two of the more interesting and 
salient facts. 
At the outset one is arrested by a photograph 
exhibiting in a marked degree that wonderful illimit- 
ability and fascinating monotony of the desert which 
is only to be likened to the corresponding spaciousness 
of ‘told ocean’s grey and melancholy waste,’”’ and one 
learns that there is good evidence to show that the 
central portion of the Estancia Valley, in New 
Mexico, with its area of 2000 square miles, was once 
the bed of a lake, at the margin of which are still to 
be seen beach ridges and other features of littoral 
formation. Debouching into this central plateau are 
a number of broad avenues, or arroyos, of gradually 
increasing depth, which extend backward to the cliff- 
edged cafions in the mountainous borderland. These 
arroyos, generally speaking, hold no permanent 
stream, but form avenues for the escape of storm 
waters, which disappear even before they reach the 
lowest level, leaving behind them the sediment and 
detritus which they carried. 
This vanished lake of New Mexico has a counter- 
part of vaster dimensions in western Utah, where, in 
the Pleistocene epoch, it is affirmed, there existed a 
lake some 20,000 square miles in area. Its surface 
was about 5200 feet above the present sea-level, or 
about 1000 feet above the present level of the Great 
Salt Lake. More or less distinct shore lines can be 
traced as the lake gradually sank and dwindled 
through the later stages of its history; two, particu- 
larly, can generally be recognised, one marking the 
time of its maximum development, and the other an 
intermediate condition. 
1 United States Geological Survey, Water Supply Papers:—No. 263, 
Surface Water Supply of Ohio River Basin, 1909; No 266, Surface Water 
Supply of Missouri River Basin, 1909; No. 267, Surface Water Supply of 
Lower Mississippi Basin, 1009; No. 268, Surface Water Supply of Western 
Gulf of Mexico; No. 273, Quality of Water Supplies of Kansas; No. 275, 
Geology and Water Resources of Estancia Valley, New Mexico; No. 277, 
Geology and Underground Waters of North-Eastern Texas; No. 279, 
Ground Water in Juab, Millard, and Iron Counties, Utah. (Washington, 
Igii.) 
NO. 2215, VOL. 89] 
In Texas there is the problem of the mounds. 
Scattered over the north-eastern portion are innu- 
merable small mounds, varying from 20 feet to 100 
feet in diameter, and from 2 to 5 feet in height. In 
general they are circular in outline, but in some 
localities they show a tendency towards elongation 
in a north-east to south-west direction. Various sug- 
gestions have been put forward to account for their 
origin: human or animal agency, water erosion, 
glacial action, wind. No definite evidence in favour 
of any one is forthcoming, and the question remains 
an open one. 
Other points might be noticed, but these few will 
suffice to show that, apart from the columns of 
figures, there are many items of interest and much 
wealth of general information contained in these water 
supply papers of the United States Geological Survey. 
THE PORT ERIN BIOLOGICAL STATION. 
pee twenty-fifth annual report of this station 
shows that it continues to be an active instru- 
ment in advancing biological teaching and research, 
sixty students and research workers having occupied 
the tables during the year. Among the several re- 
searches in progress may be mentioned a biometrical 
investigation of the variation in the shells of the 
common limpet, which shows that specimens collected 
near low-water mark are flatter than those taken near 
high-water mark, and that, contrary to expectation, 
there was no difference in height between shells 
obtained from exposed and from more sheltered posi- 
tions, if taken at the same water-level. Bidduhphia 
sinensis, a diatom from the Far East, which made its 
appearance in European seas eight years ago, and 
was recorded from Port Erin in the last report, was 
found again in quantity and in vigorous condition, in 
September and October, 1911. 
Prof. Herdman gives an account of the occurrence 
of the Peridinian Amphidinium operculatum at Port 
Erin. This flagellate organism was first observed 
there on April 7, and from this date to May 1 it 
occurred in such profusion as to form brown deposits 
in the ripple-marks on the sand at about half-tide 
level. On the same patch of sand there were, from 
June 3 to July 22, deposits similar in appearance to 
those already noticed, but on microscopic examination 
they were found to be composed of diatoms, chiefly 
Navicula (probably N. amphisbaena), and careful 
search failed to reveal the presence of any specimens 
of Amphidinium. On September 9 and 10, however, 
dense swarms of the latter organism were again pre- 
sent, but diatoms were absent, and this condition was 
maintained for a few days. On September 16 the 
naviculoid diatoms returned in force, and remained 
abundant during the two following days. By 
October 2 the diatoms had again vanished, but 
Amphidinium had reappeared, and it continued to be 
more or less in evidence until the 27th. Between 
October 28 and November 1 no _ specimens of 
Amphidinium were found, but on November 2 three 
small patches composed of this flagellate made their 
appearance in the usual positions on the beach, and 
then died away. From this date to the time of 
writing neither the flagellate nor the diatoms had 
been observed. Prof. Herdman suggests that the 
alternate occurrence, in the same area, of these two 
organisms is probably due to a physiological cause, 
and that each organism in turn exhausts or alters 
some essential constituent of the environment, so as 
to prevent its own continued existence in quantity, 
but leaves the ground suitable, or even favourable, 
to the physiological needs of the other set of compet- 
ing organisms. 
